Brake disk for a motorcycle



FIG. 1 is a perspective view showing the front, top and left side of a brake disk for a motorcycle which forms my new design;

FIG. 2 is a perspective view showing the rear, top and right side thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a front elevational view thereof;

FIG. 5 is a right side elevational view thereof;

FIG. 6 is a rear elevational view thereof;

FIG. 7 is a left side elevational view thereof; and,

FIG. 8 is a bottom plan view thereof. 

CLAIM The ornamental design for a brake disk for a motorcycle, as shown and described. 